Homodinuclear f-f and Heterodinuclear f-p Lanthanide Helicates

Lanthanide helicates are of interest due to their ability to emit either in the visible or in the NIR region. In this context it is important to prepare heterodinuclear helicates and to use them for the investigation of intramolecular communication processes between different complex units. In here we describe the ligand synthesis and self-assembly of homo- and heterodinuclear helicates based on beta-diketonate, catechol-acyl hydrazone and 2-amido-8-hydroxyquinoline Iigands. Strongly emitting homodinuclear europium(III) complexes are obtained in addition to heterodinuclear coordination compounds. Some of the latter exhibit intramolecular energy transfer behaviour with internal quenching of an aluminium trisquinolinate and enhancement of the NIR emission at an ytterbium(III), neodymium(III) or erbium(III) complex unit.